The battle for High Definition

There are two rival formats currently fighting to be the successor to DVD. On the one side, HD-DVD, the next logical step from the existing DVD technology, backed by Toshiba and the HD-DVD Promotion Group. On the opposite side, the Sony-backed Blu-Ray disc so-called because the technology uses a refined blue laser that maximises storage capabilities. Although the acronyms are different it looks likely that we’ll see a rerun of the Betamax versus VHS battle of thirty years ago.

What is HD-DVD?

HD DVD sets a new standard for next-generation optical systems that deliver brilliant, high-definition performance. Supported by the DVD Forum as the official successor to DVD, HD DVD is the next logical step in the format evolution for high capacity, high definition optical discs.

HD DVD delivers all the capacity necessary for a multitude of recorded content, including movies and live performances. There are two kinds of single-sided HD DVD discs for content playback: the 15GB single-layer disc, and the dual-layer disc with a full 30GB capacity. Using the latest compression technologies, the 30GB HD DVD disc can store up to 8 hours of HD images. Current DVDs have a capacity of 4.7GB and can contain only 2 hours of standard definition images; the 30GB HD DVD has enough room to hold an equivalent 48 hours of standard definition images.

The standard single-sided, single-layer HD DVD-Rewritable disc, with 20GB capacity, will be capable of storing approximately 5.5 hours of HD content with more capacity due in the forthcoming single-sided, dual-layer discs.

The shared disc structure of HD DVD and DVD allows full backward compatibility offering consumers the opportunity to enjoy their current DVD library and crystal-clear HD video on the same HD DVD player.

What is Blu-Ray?

Blu-Ray is the alternative format to HD DVD, offering a considerable increase in storage capacity with its 25 to 50 GB data capacity. A standard Blu-Ray disc holds 27GB of information which is about 40 times the amount of data that a CD can hold.

Although the technology is identical to CDs and DVDs, the fundamental difference with Blu-Ray is the laser that is used to read the discs. A blue laser is used instead of the usual red laser. They have a shorter wavelength than red lasers and therefore the beam can be focused on a smaller area which in short means you can fit more data on an identically sized disc.

However, the new laser means that Blu-Ray discs are not readable on standard CD and DVD players. Many Blu-Ray disc drives, however, will be backwards-compatible to enable playback of the older disc formats.

The Blu-ray Disc format offers the highest capacity out of the two formats. Blu-ray Discs are also hard coated offering a much stronger resistance to scratches and fingerprints than other existing and proposed formats. They do not require a cartridge and can be used as a bare disc, similar to DVD and CD.